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This feature will check all connected loudspeakers and cables. It makes use of an on-
board digital sine wave generator with frequency sweep.
Power output as well as the sweep range (frequency window with start and stop entry)
are selected by the user.
Selected values are also used to execute the automatic impedance control (right after
mains switch ‚on‘) if this function has been activated under [Command Mode , Page 4]
More information in‘Funcions and features guideline p.3
Within the selected frequency range and output power, the system will check the total
impedance of loudspeakers and cables connected to the speaker outputs.
The frequency sweep within the selected range will be audible through the connected
speaker system(s).
—> Beware of excessive audible output levels
The test result will be shown in the display for a period of 5sec.
Unlike in the automatic impedance control mode, any state of low impedance or short
circuit will not switch the power amplifier into ‚stand by mode‘.
The output power of the sine wave signal will however be reduced to 4W max. in order
to minimize any possible dangers for the power amplifiers. The same is true for the
automatic impedance control.
Following this test is a soft „Fade In“ of the input signal. This fade in helps to avoid any
sudden offset of extremely high volumes (high SPL from speakers) if the input damping
is set below -30dB.
Parameters
Output Power: Output power of the sine wave generator for CH.A.
Output power reading refers to 4
Ω
load for SCA-2MR.
For SCA-4MR it refers to a 2
Ω
or a 4
Ω
load - depending on Impedance Mode setting.
The accuracy of the impedance measurement will increase with rising output power.
Possible settings for power output to execute impedance measurement:
2W / 4W / 8W / 16W / 32W / 64W / 128W .